1. Field of the Invention
This invention relates generally to wrenches, such as socket, box, flare-nut, and open-end wrenches, and also ratchet wrenches.
2. Prior Art
A socket wrench set typically includes a handle with a ratchet head, and sockets of different sizes for interchangeably snapping onto the ratchet head. Each socket comprises a tubular member with internal facets for closely fitting over a nut or bolt, and a square hole in the opposite end for receiving a male connector on the ratchet head. Extension bars can be connected between the socket and the ratchet head for reaching deep into confined areas. An extension bar typically comprises a square tip at a male end for fitting into the square hole of a socket, and a square hole at a female end for receiving the male connector on a ratchet head or the male end of another extension bar. The outside surface of the female end is cylindrical, so that the extension bar tends to roll away easily when placed on a slanted surface, such as an uneven floor or the top of a vehicle.
Several inches of clearance from the end of a nut or bolt must be available for the socket to slip thereon. If not enough clearance is available, an open-end wrench may be used. A typical open-end wrench includes a handle with a pair of C-shaped wrench heads at the opposite ends. Each C-shaped wrench head includes a pair of parallel internal sides for gripping the opposite sides of a nut or bolt. The opening in the wrench head allows it to be slipped onto a nut or bolt in a a direction perpendicular to the axis thereof. However, the long handle limits the rotation of the wrench in tight spaces. The wrench heads only grip two sides of a nut or bolt, so that they tend to slip out easily or even strip the nut or bolt. Further, many wrenches of different sizes must be provided, each with its own handle, so that a complete set of wrenches is very bulky, heavy, and costly. The many variations of such wrenches require a great deal of natural resources to produce.
A box wrench is similar to an open-end wrench, except that the wrench heads are closed circular loops. A typical box wrench head includes six facets and six points (outer corners between the facets) for securely gripping all six sides of a nut or bolt. It may be repositioned on a nut or bolt in 60 degree increments. Some box wrench heads include twenty-four facets and twelve points, so that the wrench maybe repositioned on the nut or bolt in 30 degree increments when working in tight spaces. However, the long handles limit rotation, and wrenches must be provided in many different sizes, which may still be inadequate in some situations.
U.S. Pat. No. 5,626,062, to Colvin (1997) shows a ratchet wrench with a hole in the ratchet head for passing a stud. It includes a permanently attached handle which cannot be used with other tool heads. U.S. Pat. No. 5,280,740 to Ernst (1994) shows a ratchet head pivotally connected to a handle by a hinge pin. The pin is not removable, so that the handle cannot be used with other tool heads. U.S. Pat. No. 5,279,189 to Marino (1994) shows a box or socket wrench with a pivoting handle. It has all the limitations of the aforemenetioned box and socket wrenches. U.S. Pat. No. 5,152,199 to Lain (1992) shows a ratchet head for being turned by an adjustable jaw wrench. It includes no pivoting handle. U.S. Pat. No. 4,480,094 to Macor (1989) shows a socket wrench with a sliding insert for providing a total of four socket sizes. The sockets all have twelve points, and are radially aligned with each other, so that they are limited to 30 degree increments when being repositioned. U.S. Pat. No. 4,774,862 to Scull (1988) shows an open end wrench with up to nine points. It is limited to 30 degree increments when being repositioned, and its handle is fixed at an orthogonal position relative to the axis of the nut or bolt. Further, the wrench head may spread under load. U.S. Pat. No. 2,608,894 to Miller, Jr. et al. (1952) shows a simple open end wrench with a pivoting handle. U.S. Pat. No. 2,680,985 to Fish (1947) shows a ratchet wrench with five points, so that it is limited to 60 degree increments in repositioning. U.S. Pat. No. 2,549,515 to Orey et al. shows a socket wrench with a pivoting handle. U.S. Pat. No. 1,456,290 to Tell (1921) shows an adjustable wrench with only two points.